Demonstrator for indicating the effect of additive in engine oil and the like



FIG. 1 is an isometric view from an upper aspect of a demonstrator for indicating the effect of additive in engine oil and the like, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is a top plan view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a demonstrator for indicating the effect of additive in engine oil and the like, substantially as shown. 